Prime-mover-control system



3 Sheets-Sheet 1 c. B. TAYLOR ET AL PRIME MOVER CONTROL SYSTEM Filed Oct. 14, 1927 o 1 h 5 z M. 6 2., H, T v 0 M 2 M f H 7 4 a 1 3 4 Z 2 9. w /0 m 4 r .7 v a 7 n5 5 (6% V H 2 2 4 r 7 5 6 v .0 BIS I." n l l m J a A. l I v Z 5 M a 60 6 9 m. 6 am 2 a .J. a r 3 2 7 S H m. 3 a 3 a. a a 7 5 6 7 x 5 u n June 3, 1930.

Jun 3, 1930. c. B. TAYLOR ET AL PRIME MOVER CONTROL SYSTEM 3 Shets-Sheet 2 File?! Oct. 14, 1927 June 3, 1930. c. B. TAYLQR E PRIME MOVER CONTROL SYSTEM Filed Oct. 14, 1927 3 Sheets-Sheet 3 in as Patented June 3, 1930 warren STATES PATENT orr cr CHARLES B. TAY OR, 0F MILWAUKEE, AND oAnL sorrINDLER, or wnsr arms, wisooivsin, essienons TO ALLIS-GHALMERS MANUFACTURING COMPANY, or MIL- WAUKEE, Wisconsin, A CORPORATION OF DELAWARE PRIMErMOVER-CONTROL SYSTEM This invention relates to prime mover control systems, and more particularly to systoms in which the prime mover is automatically started from rest, and more specifically 5 in which the prime mover may be started either automatically or manually.

One of the objects of the invention is to provide a system of control in which the various functions will be carried out in the proper sere quence and to that end involves the provision of one or more interlocks. For example, an interlock to prevent an operation tending to open the means for controlling the admission of operating fluid to the prime mover 15 until a means for holding the admission controlling means in closed position has been released; an interlock for preventing the engagement of the gate-holding means until the gate has been closed, an' interlock for preventing the supply of power to the gateo-perating means from being shut off until the gate-hold ing means is in engaging position; an interlock to prevent the perfo-rmace of predetermined functions involved in automatic starting when the prime mover is to be started by hand; and other interlocks as will hereinafter appear.

Another object is the provision of means whereby the power furnished by the prime 'mover may be limited and adjusted to any desired value within the range of the prime mover, and more specifically whereby such means may be a part of elements utilized in the automatic starting of the prime mover. A further more specific object is the provision of means whereby the power limiting means may be operated through remote control. or manually.

Still another object. is the provision of means preventing waste of operating fiuid for the prime mover or possible damage due to undesirable starting of the prime mover.

A further object is the provision of control means for a prime mover which is compact and occupies a relatively small amount of space, and which may be disposed in a single box or housing.

Other objects will appear hereinafter as the description of the invention proceeds. The novel features of the invention will ap- Lil I in) Application filed October 14, 1927. Serial to. 226,083.

pear from this specification and the accompanying drawings forming a part thereof and showin several embodiments of the invention, am all these novel features are intended tobe pointed out in the claims.

In the drawings:

Fig. 1 is a front elevation in diagrammatic form, of a control system embodying the invention as it may be applied in the control of a prime mover.

Fig. 2 and Fig. 3 are detail views of certain lever assemblies used in the system shown in Fig. 1, Fig. 2 being a front elevation and Fig. 3 a side elevation.

Fig. 4 is a side elevation of a remote control drive for certain parts of Fig. 1. I

Fig. 5 is a modified control system embodying the invention, shown in diagrammatic form, parts unnecessary to an understand ing of the modification having been omitted.

Fig. 6 and Fig. 7 are detail views of another lever assembly, Fig. 7 being a side elevation and Fig. 6 being a front elevation except that in Fig. 6 certain levers have been omitted for the sake of clearness.

Fig. 8 and Fig. 9 are detail views of one of the levers shown; in Fig. 7, Fig. 9 being a front elevation and Fig. 8 a top view.

Fig. 10 is a front elevation of another of the levers shown in Fig. 7.

Referring to Fig. 1 of the drawings, a prime mover 19 is here indicated as a hydraulic turbine having a shaft 20 adaptedto drive a device such, for example, as an electric generator. The turbine is supplied with water through a conduit 21 in which is interposed means for controlling the admission of water to the turbine, this means being here shown for the sake of simplicity as a valve 22, it being understood that the turbine may be controlled by other forms of gates including the usual guide vanes in thecase of a hydraulic turbine. For the sake of brevity the means for controlling the admission of operating fluid will hereinafter be termed a gate. The gate 22 is pivoted at 23 and inasmuch as it is customary to so mount the guide vanes of a turbine that when they are closed the water pressure tends to open the guide vanes, the pivot 23 has been shown somewhat off center whereby the gate 22 would tend to open to a certain extent under water pressure. The gate 22 may be swung by means of a crank 24 to which is pivoted a connecting rod 25 in turn pivoted to a piston rod 26 of a servomotor 27. This servo-motor may be of any desired form, including, for example, one or two pistons. In the instance illustrated two pistons 28, 29 are provided operating in cylinders 30, 31 respectively.

The servo-motor 27 may be controlled by means of a regulating valve 17. This valve is here shown as including a cylinder 32 in which are disposed two piston valves 34, 35 movable in unison and operable by means of a valve stem 33. The cylinder .32 has a pair of ports to which are connected respectively pipes 36, 37. In the position of the parts illustrated these ports are somewhat below the piston valves 34, 35, respectively. The pipe 36 is connected to cylinder 30 and the pipe .37 is connected to cylinder 31 of the servo-motor. The regulating valve cylinder 32 is also provided with drain ports, respectively above and below the ports 36, 37, to which are connected respectively pipes 38, 39, in turn connected to a drain pipe 40.

The servo-motor 27, and other parts to be hereinafter described, may be supplied with fluid under pressure through a pressure supply pipe 41 fed from a pressure tank (not shown) of any desired form. The supply of pressure fluid may be controlled by means of a shut-off valve 5 interposed in the pressure supply pipe 41. The shut-oil valve is here shown as hydraulically operable by means of a piston 42 disposed in a cylinder 43. The piston 42, and consequently the shut-01f valve 5, is biased to the closed position by means of a spring 44. Pressure fluid may be supplied to cylinder 43 through a pipe 45 connected to the pipe 41. In the pipe 45 is interposed a two-way valve 46, which. in the position shown, is adapted to admit pressure fluid to cylin ler 43 and to close a drain pipe 47. The valve 46 is operable to the other of its positions by means of a lever 48 which when moved a PI'GClQtGIHllDGCl amount in a counter-clockwise direction causes valve 46 to cut off pressure fluid from cylinder 43 and connect said cylinder to the drain pipe 47. The lever 48 may be operated by means of a piston 49 disposed in a cylinder 50. A spring 51 is provided for biasing piston 49 to a position in which lever 48 cuts off pressure fluid from cylinder 43. Cylinder is connected by means of a passage providing the admission of pressure fluid at a slow rate to cylinder 50 from the pipe 45. The cylinder 50 also has connected thereto a pipe 53, the relation of which to the remainder of the system will be hereinafter described. The shut-off valve 5 may be operated in other desired manners.

Returning now to the regulating valve 17,

the valve stem 33 of this valve is here shown as provided with a spring cage 54 at the upper end thereof. Vithin the spring cage 54 is a compression spring 55. A rod 57 extends into the spring cage 55 and is provided at its lower end with a collar 56. The rod 57 extends upwardly through a swivel connection 58. The'rod 57 may also be threaded and provided with a nut 59. Between the swivel connection 58 and a collar 185 a compression spring 60 is provided. The swivel 58 is carried by a floating lever 61 having a floating pivot 62 which may be raised and lowered by means of fly balls 63. The fly balls 63 may )8 rotated in any suitable manner so as to rise and fall in speed in accordance with the prime mover 19. In the illustrated showing, the fly balls are driven by means of a belt 64 from the shaft 20. The other end of the floating lever 61 has suitably swiveled thereto a piston rod 65 of a dash pot 66 or compensating device. The lower end of the dash pct 66 has pivotally connected thereto a connecting rod 67 in turn pivoted to a relay lever 68. The other end of the lever 68 may be operativcly connected to the gate 22 by means of a rod 69 and a crank 70. Movable in unison with lever 68 is a lever 71 adapted to transmit a connecting rod 74 in turn pivoted to a camlike member 75. The member 75 is adapted to pass through a slot or hole 76 in the valve stem 33, the valve stem being, it necessary, enlarged for this purpose. It will be noted that the vertical dimensions as viewed in the present illustration, of the cam-like member 75 determine the amount that the regulating valve stem 33 may be moved for any given position of gate 22. The rate-limiting dev ce as illustrated in Fig. 1 is not per so our invention but is lnoadly claimed in an application of Arnold Ptau, Serial. No. 754,538, filed Dec. 8, 1924. The rate limiting device. however. is an element of novel combinations disclosed in the present application.

In order to control the position of valve stem 33 during the starting and stopping operations of the turbine 19, this stem is here shown as provided with a collar 77 the under side of which, in the illustrated instance, is engaged by a pivoted control finger 16. It may be here mentioned and as ill be obvious from a consideration of the operation of the system to be hereinafter described. that the position and direction of action of the control finger 16 will depend on the direction in which the valve stem 33 must be moved in order to respectively cause the servo-motor 27 to open and close the gate 22. Correto alever provided with a pivot 80,.

regulating valve 17 so as to close the gatev 22. Correspondingly, the connection between the valve stem 33 and the floating lever 61 must be properly designed to take account of the desired motions relatively to each.

other of the valve stem 33 and that caused by the fly balls 63 so that, for example, an increase in speed will cause the fly balls to move the regulating'valve 17 so as to close the gate 22 a predetermined amount. The control finger 16 may be biased as here shown in a counter-clockwise direction by means of a spring 16.. Such motion of control finger 16 is prevented when the turbine 19 is at rest and before the starting controlaction has been initiated, by means now to be described. The control linger 16 is here shown as of the bell crank form and has pivotally connected thereto a connecting rod 79 in turn pivoted The lower end of lever 80 has pivotally connected thereto a link 81 the other end of which link is pivotally connected to one end of a floating lever 82. The parts just described are visible in the assembly view of Fig. 1, but these parts, and others to be described, are more clearly shown in detail in Figs. 2 and 3. The floating lever 82 has a floating pivot 83 and the lower portion 82 of the floatinglever is adapted to engage a pin 84 carried by a relay lever 85. The lever 85 is freely rotatable about a shaft 86 and an extension 85,, of the hub of lever 85 is adapted to carry and have fastened thereto. a lever 87 (see Fig.1). The lever 87, and consequentlyalso lever 85, is positioned in accordance with the position of the gate by means of a connection here shown as aconnecting rod 88 pivoted at one end to lever 87 and at the other to lever 68. The floating pivot 83 is associated with a lever 89 which is pinned, by a pin 90, to the shaft 86. The lever 89 has a lateral extension 8 adapted tobe controlled by a piston 7 It also has a lateral extension 8 in the other direction provided with a cam 9 one portion of which has a depression or notch 91 adapted to receive a roller 92. The

. roller 92 is carried by a lever 10 pinned to a shaft 94. See also Figs. 6 and 7. It may be noted that the side elevation, Fig. 7, shows all of the levers carriedby shaft 9'4, whereas in the front view, Fig. 6, the levers 105, 107, and 2 have been omitted for the sake of clearness, these latter levers being however shown in Fig. 10, and Figs. 8 and 9 respectively, as will appear. The lever 10 is provided with an axially extending lateral projection 95 which carries a screw 96 adapted to engage a lever 97. The lever 97 is biased in a counterclockwise direction by means of an adjustale spring 98. The spring 98 may be adjusted from the exterior of the indicated wall of a box or casing 183. The lever 97 is provided with a lug 179 adapted to be engaged by a lug 178 on lever 85 as shown in Fig. 1, for a purpose to be described. Also fastened to shaft 94 is a lever 99 provided with a hole 100 in the end thereof. The hole 100 is adapted to pivotally receive a valve stem 101 adapted to operate a valve 11. The lever .19 also carries an axially extending pin 102 for a purpose to be hereinafter noted. The lever '99, and consequently the shaft 94, is biased in a clockwise direction by means of an adjustable spring 104 suitably fastened to a stationary element such as the casing 183 and to a pin 103 carried by lever 99. The shaft 94 also carries a lever 105 which lever is freely rotatable about said shaft. t one end of lever 105 is mounted a radially extending roller 106. From its hub the lever 105 has a lateral extension 107 (see Fig. 10) having an end portion 108. The lateral extension 107 is provided with an axially extending hole 109 adapted to receive that portion of pin 102 which extends toward the right (as viewed in Fig. 7 of lever 99. As shown, the hole 109 is considerably larger than pin 102 so that movement of lever 99 in a counter-clockwise direction as viewed in Fig. 6 is permitted. The shaft 94 also carries a lever 2 which is freely rotatable about said shaft. The details of lever 2 are shown inFigs. 8 and 9 the first mentioned View being arplan and the second a front elevation similar to that of Fig. 1. The lever 2 is provided with a hole 110 adapted to reive a rod r alve stem adapted to operate valves 3 and 4. The rod 111 is pivotally carried by lever 2 on a pin 112. The lever 2 is also provided with a hole 113 adapted to receive a pivot pin passing through a bifurcated member 114 carried by a rod 115 in turn connected to the core of a solenoid 1., The lever 2 may be biased in a clockwise direction by means of a spring 184 connected to a pin 116 carried by said lever. The spring 184 has not been shown in Fig. 1 in order to avoid confusion. The lever 2 also is provided with a screw 117 passing through said lever from the upper to the lower side 7 maximum predetermined gate opening which it is desired not to have exceeded no matter what the load on the turbine may be, the following mechanism is provided. A shaft 119 rotatable by means of a hand wheel 120, cary direction.

as soon as movement of nut 121 ceases.

ries a threaded nut 121 on a screw threaded portion of shaft 119. The nut 121 is provided with a pin 122 extending therethrough and laterally from the sides of the nut and this pin is adapted to engage the transverse slot 125 (see Fig. 2) in the bifurcated end 123, 123 of a lever 124. The bifurcations of lever 124 are clearly shown in Fig. 3. The lever 124 is loosely mounted on shaft 86 and is provided with a wide keyway 126 the sides of which keyway are adapted to engage a key 127 in shaft 86. The right hand bifurcation 123 of lever 124, as viewed in Fig. 3, is provided with an extension 128 for a purpose to be hereinafter noted. The lever 124 is also shown as being provided with a projection 129 on the hub thereof this forming a convenient mounting for an indicator lever which may be fastened to the projection 129 by a screw in the tapped hole 130. The indicator lever has not been shown in view of the fact that it would cover up and confuse the remaining mechanism inasmuch as it lies in front of the mechanism so that the end of the indicator lever will be visible through an opening in the cover (not shown) of the casing 183 for the control mechanism. For the sake of clearness, only a fragment of the casing 183 has been shown in Fig. 1. The shaft 119 is provided with two stops 131 on either side of the nut 121 so as to limit the amount of travel of the nut. It will be noted that if the shaft 119 is rotated so as to move the nut 121 toward the left as viewed in Fig. 1, the right hand side of keyway 126 will eventually engage the key 127 and move the lever 8 in aclockwise direction. This will cause similar movement of the floating pivot 83 (through the lever extension 89) thereby causing the floating lever 82 to tilt in a countor-clockwise direction about the .pin 84. The pin 84 is for the time being fixed inasmuch as it remains stationary as long as the gate 22 remains stationary due to the connection between lever 85 and the gate, previously described. As the floating lever 82 tilts in counter-clockwise direction it causes lever 80 to swing in a clockwise direction thereby moving control finger 16 in the same This movement of control finger 16 is in such direction as to move the regulating valve 17 toward the position in which fluid is admitted to cylinder thereby moving the gate 22 toward closed position. As the gate moves toward closed position the pin 84 of course moves clockwise so that floating lever tends to tilt clockwise and therefore control finger 16 will leave the regulating valve 17 in the neutral position It will therefore be clear that if the nut 121 is moved sufiiclently toward the left that the gate 22 will be completely closed. On the other hand, if the nut is moved toward the 1 right the control finger 16 will be moved in a counter-clockwise direction under the influence of spring 16 thereby freeing the collar '77 for movement to any position within the control range of valve stem In other words, if the nut 121 is moved as far to the right as stop 131 will permit the gate 22 may be opened to its full extent by the fly balls 63 if the load so requires it.

A shaft 132 suitably journaled in the walls of the casing may be swung a predetermined number of degrees by means of a handle 133. The shaft 132 carries a cam 134 which when the shaft 132 is swung is adapted to engage roller 106 thereby swinging lever 105 in a counter-cloclnvise direction. In the position of the parts shown in Fig. 1, however, it would not be possible to move the handle 133 to swing lever 105 for the reason that the end portion 108 of lever 107 is underneath the right hand bifurcation 123,, as viewed in Fig. 3, of lever 124. This interlock, for a purpose to be hereinafter set forth, is effective when the lever 124 is in any position except that corresponding to full gate opening, that is except when the lever 124 is in the extreme right hand position. In this position the end portion 108 may be lifted past the left hand edge 128 of the said right hand bifurcation 123,. The extension 128 is provided so that end portion 108 is blocked from upward movement when the nut 121 is in its extreme left hand position, as viewed in Fig. 1.

The shaft 119 may also be rotated from a remote control point by means of a remote control mechanism 135. This mechanism includes a motor having a. shaft 136 adapted through the gearing indicated to drive a shaft 137. The remote control mechanism is shown in detail in the side elevation, Fig. 4. The shaft 137 carries a worm 138 adapted to drive a worm wheel 139. The worm wheel 139 is rotatably mounted on a relatively movable hub 140. The connection between the worm wheel 139 and hub 140 is provided by means of a roller 141 seated, in the position of the parts as shown in Fig. 4, in a complementary notch in the inner periphery of the worm wheel 139. The roller 141 is biased outwardly by means of a compression spring 142 disposed in a radial hole 143 in the hub 140. The hub 140 is suitably connected to the shaft 119. As the motor rotates the shaft 136 in one direction or the other as may be determined by suitable electrical connections (not shown) at the control point, the worm 138 drives the shaft 119 in either one direction or the other through the roller 141. The relation of the roller 141 to the associated parts is such that if it is desired to rotate the shaft 119 by the hand wheel 120 the hub 140 will force the roller 141 out of the slot in the worm wheel thereby permitting rotation of the shaft 119 which would otherwise not be possible by reason of the fact that the worm wheel 139 could not rotate the worm 138.

The valve 4 which is adapted to be operated by lever 2 is here shown as including a cylinder 144 at the lower end of which (here shown as somewhat enlarged) is a centrally located port 145 which is connected to the pipe 53. The port 145 is adapted to be closed by means of'a needle valve 3 which is movable in unison with the valve 4. The end of the needle valve operates in the enlarged portion of the cylinder 144 and the upper end of the needle has an oil tight fit with the portion of the cylinder 144 above the enlargement. The enlarged portion of cylinder 144 is provided with a drain port 146 connected to 'a drain pipe 40... The cylinder 144 is also provided with a port 147, which in the position of the parts shown has been opened by the upward movement of the valve 4. The same movement has uncovered the admission port 148 which is connected to a pressure line6 in turn connected to the pressure pipe 6. The port 147 is connected by means of a pipe to a port 149 in a cylinder 150. The cylinder 144 is also provided with another drain port 151 which in the position of the parts shown is above the valve 4. The drain port 151 is also connected to the drain pipe 40 It will be noted that when the needle valve 3 is. seated in the port 145 the valve 4 will be in a position to close communication between the admission port 148 and the port 147, and will connect the port 147 with the drain port 151 thereby draining cylinder 150. Moreover, if the lever 2 descends sufficiently merely to strike piston 14, the action is the same as far as ports 148, 147 and 151 are concerned but the needle valve 3 will not be closed. In the cylinder 150 is disposed a piston provided with a piston rod 152 having at the upper end thereof a collar 153 which in the position of the parts shown engages the upper side of the bifurcations 154 (see Figs. 2 and 3) of the lever 8. The piston rod 152 is biased downwardly by a spring 181 acting at its low er end against a collar 180 carried by said rod. The upper end of spring 181 acts against a cylinder 155 which is larger in diameter than cylinder 150 as here shown, and it may be made integral with cylinder 150. The cylinder 155 contains a piston 15 biased by means of the compression spring 156 acting against the top of the piston and againstthe inner upper side of the headof cylinder 155. The cylinder 155 is provided with a port 157 located beneath piston 15. In order to provide for an appropriate amount of space for the admission of pressure fluid beneath piston 15 a screw or other stop 182 may be provided on said piston. The piston 15 is provided with a downward tubular extension having a sliding fit in the cylinder 150. A predetermined amount of space is left between the lower end of piston 15 and the upper side of piston 7.

Inasmuch as it is desirable to cut off pressure fluid from the pipe 6 so as to prevent leakage, and inasmuch as the valve 22 may tend to partially open under hydraulic pressure, a pivoted latch 159 is provided and this latch is adapted to engage a hump or notch 160. Inorder to permitopening of the gate 22, automatic means are provided for releasing the latch 159 including, as here shown, a piston 12 operating in a cylinder 161. The

cylinder 161 is provided with an admission 7 port 162 connected by means of a pipe 163 to a port 164 in a cylinder 165 in which the valve 11 operates. The cylinder 165' is also provided with a port 166 disposed beneath the valve 11. The port 166 is connected by a pipe 7 167 to the pressure line 6 The cylinder 165 is also provided with a drain port 169 disposed above valve 11 and connected by a pipe 168 to the drain 40 In the position of the parts shown the port 164 is connected to the drain port 169 and the valve 11 prevents pressure fluid from flowing from port 166 to port 164. Lifting of valve 11 cuts off communication with the drain port 169 and connects ports 164 and 166 so that pressure fluid may be admitted to cylinder 161.

Operating in unison with piston 12 is a piston valve 13- operating in a cylinder 170. The cylinder 170 is connected by means of a pipe 171 to the pressureline 6 The cylinder 170 is also provided with a port 172 connected by a pipe 173 toa cylinder 174 in which a plunger piston 14 is adapted to operate. The cylinder .170 is provided with another port 175 connected by a pipe 176 to the p'ort157 in cylinder 155. The ports 172 and 175 are so located that when the latch 159 is in latched position the piston valve 13 prevents the flow of pres sure fluid from pipe 171 to either of the said ports. Moreover the cylinder 170 is provided with a drain port 177 so that in the said position both ports 172 and 175 have been connected to this drain port. Communication between the drain port 177 and ports 17 2 and 175 is successively cut ofli when the piston valve 13 moves toward the left, as viewed in Fig. 1.

The lever assemblies on shafts 86 and 94 respectively is one of the features that render the apparatus very compact. It may be noted that in 1 some of the levers, links, etc., are drawn somewhat out of proportion without affecting in any way the principles involved or the understanding of the invention. This has been done merely for the sake of clearness and to prevent any excessive over lapping of parts. For example, the lever 2 is much larger than it need he so that the elements 11, 7, 15, 3, 4,and 14 may be shown side by side.

The operation of the system will be first considered in connection with the condition that the prime mover 19 is at rest and the gate 22 is closed. lVhen the prime mover is at rest the fly balls 63 are in their innermost position so that they have moved the floating pivot 62 to its lowest position, the floating lever 61 having swung in a counter-clockwise direction about the pivot at the end of piston rod 65. Consequently spring 60 is compressed and the rod 57 tends to move in a downward direction. Such motion is prevented by the control finger 16. The reason control finger 16 cannot swing in a counterclockwise direction under the influence of spring 16 and spring 60 is that the counter clockwise tendency of lever 80 tends to move floating lever 82 in a clockwise direction about the relatively fixed pivot 84 but the movement of the floating pivot 83 is prevented by the fact that lever 889 cannot move in a counter-clockwise direction, being prevented from doing so by means of spring 181 acting through rod 152. The needle valve 3 and also the valve 4 are shown in Fig. 1 in the position which they occupy at the moment that the solenoid 1 has been energized and therefore lifted the lever 2. As soon as fluid pressure is released from cylinder 50 the spring 51 acts to expel the fluid from said cylinder through pipe 53, port 145, to drain port 146. The consequent operation of valve 46 connects cylinder 43 with drain pipe 47 and the pressure fluid in pipe 41 acting against piston 42 opens the shut-off valve 5.

The opening of the shut-off valve 5 admits pressure fluid to pipe 6 and pressure line 6... The regulating valve 17 being in the position as shown permits pressure fluid to flow from pipe 6 through pipe 36 into cylinder 30 thereby firmly seating gate 22 in fully closed position. This relieves the back pressure of the notch 158 on latch 159. The valve 4 being in the position shown permits admis sion of pressure fluid from line 6 through port 148 to port 147 to port 149. Consequently piston 7 rises until it strikes the lower end of piston 15. The area of piston 7 and the pressure upon it are not large enough to cause lifting of piston 15 against the additional resistance of spring 156. Lever 8 is consequently permitted to move a predetermined small amount in a counterclock wise direction. This amount of movement is sufficient to cause the cam 9 to move lever 10 in a counter-clockwise direction enough to lift the Valve 11 thereby admitting pressure fluid to port 162 and consequently moving the latch 159 in a counter-clockwise direction out of the notch 158. This amount of movement of lever 8 is however not enough to permit the regulating valve 17 to move, or if moved to cause any movement of servo motor 27. It will be noted that the lost motion between the collar 56 and cage 54 must first be taken up before stem 33 will be permitted to move downwardly. A predeten mined movement of latch piston 12 causes valve 13 to admit pressure fluid through port 172 to cylinder 174 thereby causing piston 14 to rise. The piston 14 does not rise sufliciently to touch screw 118. The purpose of this action of piston 14 is important in the stopping operations and will be set forth hereinafter.

When the latch 159 has been fully released the valve 13 is in a position to permit the ad mission of pressure fluid to port 175 thereby causing admission of fluid to cylinder 155 and the lifting of piston 15 to the full extent permitted by spring 156. Piston 7 of course follows, lifting rod 152, thereby freeing lever 8 for movement in a counter-clockwise direction. Control finger 16 then swings in a counter-clockwise direction under the influence of spring 16, and completely frees the collar 77 for movement under the influence of spring 60. The amount of counter-clockwise movement of control finger 16 is determined by the relative position of a keyway 126 and the key 127. This relative position depends, as has already been described, on the position of the nut 121. Thus, the maximum permissible gate opening may be set for any desired fraction, usually expressed in tenths, of the full gate opening. It may be noted at this point that pressure fluid is not admitted to cylinder 155 until the latch 159 has been fully released and consequently the latch must be fully released before the control finger 16 is permitted to move as has been described.

The downward movement of stem is preferably limited in some way in order that in the starting owration the prime mover may be brought up to the desired speed at a desired rate. This is particularly true after the prime mover has been broken away from its bearings and. it is driving an alternating current generator which is preferably brought gradually to synchronous speed with the line to which it is to be connected. The downward motion of stem 33 is limited by the cam which may be of any desired form. In the particular form illustrated :suflicient downward movement of stem 33 is permitted with the gate 22 in the closed position, so that the regulating valve 17 will admit the desired amount of pressure fluid through pipe 37 to cylinder. 31 so that the gate 22 is moved toward open position. As the gate moves toward open position the rod 69 causes the cam 75 to move toward the left and, depending upon the shape of the cam, permits a greater or less admission of fluid under pressure to cylinder 31 as the gate 22 proceeds toward its predetermined maximum opening.

As the gate opens, the pin 84 will more in a counter-clockwise direction thus tilting floating lever 82 about pivot 83 in a counterclockwise direction, and therefore moving As the speed of the prime mover 19 rises from rest the servo-motor 27 of coursealso comes under the control ofthe fly balls which regulate the position of the valve stem 33 in r the usual manner. Compensation is also accomplished in the usual manner. by the relay action of the gate movement on the floating lever 61 through the relay lever 68and dash pot 66.

In considering the operations involved in automatically stopping the prime mover 19, the parts will be in the position they have after the completion of the starting operations, hereinbetore described. Letit be assumed that the load on the prime mover is steady so that the regulating valve 17 is in the neutral position in which both of the ports 36, 37 are closed, the gate 22 being in a predetermined open position, and the control finger 16 leaving the collar 77 free from movement and control by the fly balls, except inv so far as the control finger 16 will be moved into engagement with collar 77 in case the fly balls should attempt to open the gate 22 to an extent greater than the pre determined limit. It now the solenoid 1 is deenergized the lever 2 will drop, the screw 118 striking the piston 14 and further downward movement, for the time being, of lever 2 being thereby prevented. In this position of lever 2 the valve 1 is closed, that is, communication between port 1 18 and port 147 is closed and communication is established between ports 1417 and 151 thereby permitting piston 7 to descend under the influence of spring 181. It may be noted,however, that the downward movement of lever 2 is not sufiicient to close needle valve 3. This downward movement is of course adjusted by screws 118. The lever v8 is' thereby swung in a clockwise direction causing the cam 9 to take the position shown in'Fig. 1.

The lever 10 does not, however, swing clock- WIEG under the influence of spring 104 at this time for the reason that ,the lever 97, biased by the stronger spring 98, holds the lever 10 out of the notch 91 so that the valve 11 does not close at this time. The lever 97 is permitted to act against lever 10 by reason of the fact that'the projection 178 on lever 85 is not in engagement with. the projection 179 of lever 97, when the gate 22 is in open position.

Rotation of the lever 8 in a clockwise direction causes the floating lever 82 to tilt in a counter-clockwise direction about the relatively fixed pin 84 thereby causing control finger 16 to move the regulating valve 17 into the position in which pressure fluid is admitted to cylinder 30. The gate 22 consequently moves toward its closed position at a rate determined by the rate, limiting device 18. When the gate is fully closed the projection 178 has moved the lever 97 sufficiently in a clockwise direction to thereby permit lever 10 to move in the same direction, under the influence of spring 10.4, roller 92 then entering notch 91. The valve 11 is thereby closed, that is, it returns to the position shown in Fig. 1 in which pressure fluid is cut ofl from port 16 1, and that port is connected to drain port 169. The spring 160 consequently moves the latch 159, along with piston 12 and piston valve 13. The initial movement of latch 159 toward latched position causes valve 13 to connect port 175 with the drain 177 thereby draining cylinder 155 and allowing piston 15 to descend. When the latch is in the fully engaged position the piston valve 13 has cut off communication between pipe 171 and port 172 and has further permitted communication between port 172 and the drain port 177, thereby draining cylinder 17 4; The lever 2 is thereby permitted to close the needle valve 3 preventing further draining from cylinder 50. As the pressure builds up in the cylinder 50 due to the connection between it (through pipe 52) and pressure supply pipe 41, the valve 48'is swung to the position shown in Fig. 1 thereby admitting pressure fluid to cylinder 13 which then closes the shut-off valve 5.

In case the gate latch 159 should break or for some other reason the gate 22 should not be held in the closed position when the prime mover is at rest, the rod 88 will swing the lever in a counter-clockwise direction as the gate opens thereby permitting the lever 97 to move levers 10 and 99 in a cou'nter-clockwise direction. This movement causes pin 102 to lift the lever 2 (by engaging screw 117 on lever 2) suflicient-ly to open the needle valve 3 (but not valve 4) thereby causing opening of the shut-off valve 5. The regulating valve 17 being provided with pressure fluid, the latter is admitted to cylinder 30 thereby again returning the gate 22 to the closed position. It will be noted that under these conditions none of the parts which cause starting of the prime mover is operated.

If it is desired to start the prime mover by hand control, the hand wheel 120 is first rotated in the proper direction to move nut 121 to the right as viewed in Fig.1, until the indicator shows full gate opening. It is of course understood that the gate is closed at this time and that the lever 2 is in its lowest 7 position, the solenoidl being deenergized. All other parts are in the position shown in Fig. 1. The nut 121 having been moved as stated, the portion 128 of bifurcated lever 124 is in a position to permit counter-clockwise movement of lever 107. Such movement may now be caused by turning handle 133 thereby causing cam 134 to engage and move roller 106. The lower surface of hole 109 then engages the pin 102 thereby rocking lever 99 counter-clockwise. The pin 102 also lifts lever 2 sufficiently to cause needle valve 3 to open which in turn causes the shut-0E valve 5 to open. The lever 99 having opened valve 11 and pressure fluid being now supplied to the line 6 the piston 12 is moved to release the latch 159. The prime mover may now be started either by manually pulling the valve stem 33 downward against the resistance of spring 55 to thereby move the regulating valve 17 to the gate-open position (this might be done in emergency cases) or by using an auxiliary regulating valve (not shown) in shunt with regulating valve 17 and normally hydraulically disconnected from the pressure line 6 and the servo-motor 27. The auxiliary regulating valve may be compensated by connection with the gate, as is the valve 17, in the usual manner but such an auxiliary valve is old in the art and has therefore not been shown.

Referring now to Fig. 5 which shows a somewhat modified form of the control system of Fig. 1 it may be noted that the prime mover along with its gate. and the speed governor are not shown in this figure inasmuch as after a description thereof the relation of the parts may be readily seen. Those parts which are identical with those in Fig. 1 have been given the same reference characters so that it will be sufficient to describe the differences that exist. The gate latch 159 is similar to that in Fig. 1 except that the parts have been reversed inasmuch as the piston rod 26 is adapted to be moved by the gate-operating servomotor (not shown) toward the right to open the gate instead of towards the leftas in Fig. 1. The regulating valve 17 and the shut-off valve 5 are indicated in outline.

The mechanism within the casing 183 is provided with a floating lever 185 corresponding to lever 82-82 in Fig. 1. The floating lever 185 has an upper pivotal point connected by means of a connecting rod 186 through a turn buckle 187 to a crank for swinging the control finger 16. The floating pivot 83 is connected by means of a link 188 with the lever 89. The floating lever 185 is provided with an extension 189 provided at the end thereof with a roller 190 adapted to engage a cam 191 mounted on the hub of the lever B. The lower end of floating lever 185 is connected pivotally to a relay rod 192. This rod may be connected to a relay lever such as 68 (see Fig. 1) or any other part associated with the gate so that opening movement of the gate will tend to cause motion to the right of rod 192.

For hand starting, a lever 193 operable by a handle 194 is provided. The lever 193 is adapted to engage a rod 195 slidably mounted in suitable bearings, and this rod is adapted to swing a lever 196 in a counter-cloelnvise direction. The lever 196 may be keyed to the same shaft with a lever 10 (corresponding to lever 10 in Fig. 1) or may be otherwise functionally integral with lever 10,... The lever 196 has pivotally connected thereto a rod 197 having a lost motion connection with a pivoted lever 198. The end of rod 197 is provided with a nut 199 to adjust the amount of possible lost motion. The lever 198 is movable in unison with the lever 2 operable by a solenoid 1 as in Fig. 1.

An interlock is provided between means for predetermining the permissible gate opening and the hand operated means 194. This interlock includes an extension 200 on lever 193, adapted to engage a collar 201 on a screw 202 which screw is here shown as in threaded engagement with a boss on the easing 183. The screw 202 is operable by means of a hand wheel 203 and is adapted to be engaged by the lever 8 after predetermined movement in a counter-clockwise direction of said latter.

The lever 8 is provided with an extension 8 and a cam 9 thereon as in Fig. 1. The notch 91 in the cam corresponds to the similar notch in Fig. 1 and is adapted to be engaged by the roller 92. Mounted loosely on shaft 86 is an additional cam member 204 which also has a depressed portion 206 similar to 91 in cam 9. The cam 204 is operable in a counter-clockwise direction by means of a rod 205 which may be connected to move in accordance with the position of the gate so that as the gate moves toward the open position the rod 205 will move toward the left. The purpose of the additional cam 204 will appear hereinafter in connection with the description of the operation.

The operation of the system shown in Fig. 5 is as follows: Vhen the solenoid 1 is energized the lever 2 is raised thereby opening the needle valve 3 and the valve 4, as shown in said figure. The opening of needle valve 3 causes opening of the shutoff valve 5 thereby supplying pipe line 6 with pressure fluid. The previous opening of valve 4, pressure fluid being now present in line 6... admits fluid to cylinder 7 The piston 7 rises till it strikes piston 15. Lever 8 moves in the counter-clockwise direction a predetermined amount thereby moving earn 9 and lever 10 to thereby open valve 11. The opening of valve 11 causes piston 12 to move the gate latch toward the released position and in so doing the valve 13 admits pressure to raise piston 14. When the latch is entirely released the valve 13 admits pressure below piston 15 raising the same to cause further counter-clockwise movement of lever 8. This movement causes similar movement of control finger 16 thereby freeing the stem 33 of the regulating valve 17 for movement to the gate-open-position. In the modification of Fig. 5 the amount of movement of the valve stem 33 is controlled in a somewhat different manner than in Fig. 1. It will be noted that as lever 8 moves in a counterclockwise direction the floating pivot will tend to move toward the right as viewed in 7 this figure. The amount of this movement and therefore the amount of counter-clockwise movement of control finger 16, is limited by the amount of movement possible before roller 190 engages cam 191. This may of course be any selected amount depending upon the shape and position'of the cam and also upon the turn buckle 187. The relay rod 192 being controlled by gate position, consequently determines the speed of the gate for any position it assumes as it moves toward the open position.

After the prime mover has been started and the gate has been opened a predetermined amount, the rod 192 will have been moved toward the right a predetermined amount and it will be noted that if the lever 8 is in engagement with the screw 202 further movement toward the right of rod 192 will cause floating lever 185 to rock about the floating pivot 83 thereby causing motion of the control finger 16 in such direction as to bring the regulating valve 17 into the neutral position thereby stopping any further opening movement of the gate. In this respect the power limiting mechanism is simllar to that shown in Fig. 1.

In case the latch 159 should break and tail to hold the gate closed when the unit is at rest, the rod 205 being connected. with the gate, will be moved toward the left a SLlffiClGIlt amount to cause counter-clockwise movement of lever 1O thereby causing rod 197 to swing lever 2 sufiiciently to open the needle valve 3. The shutoff valve 5 is thereby opened and the regulating valve 17 admits fluid pressure to the servo-motor to cause the same to hold the gate shut as described in connection with Fig. 1.

The operations involved in stopping the unit are similar to those already described in connection with Fig. 1 and it is not believed necessary to repeat-them for that reason.

As far as hand starting is concerned, the hand wheel 203 must be rotated in the proper direction so as to move screw 202 away from lever 8 a suflicient amount so thatthe position of screw 202 corresponds to full gate opening. Inthis position of the collar 201 it will be possible to cause eflective actuation of lever 196 through handle 1%. This operation does'no more than 'cause'the needle valve 3 to open the shut-off valve 5, and the valve 11 to cause release of the latch, thus preparing the system for hsmdcontrol in a obvious modifications may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent:

1. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for operating said gate, means for releasably holding said gate in closed position, means including a motive device for controlling said gateoperating means, means for supplying motive power to said motive device, and means for preventing the supply of motive power to said motive device, until said holdingmeans has been released.

2. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for operat ing said gate, means for releasably holding said gate in closed position, means for controlling said gate-operating -means, means operable by pressure fluid for controlling said gate-operating controlling means, and means operatively related to said holding means for controlling saidpressure fluid operable means.

'3. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for operating said gate, means including a motive .de vice for releasably holding said gate in closed position, means for supplying motive power to said motive device, and means operatively related to said gate for so controlling --the supply of power to said motive device that movement of said holding means toward holding position is prevented until saidgate is closed.

4. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for operating said gate, means for releasably holding said gate in closed position, means operable by pressure fluid for actuating said holding means, a valve for controlling the supply of pressure fluid to said actuating means, and means operatively related to said gate for controlling said valve.

5. In a control system for a primemover having a gate for controlling the admission of operating fluid thereto, means for operating said gate, means for releasably holding said gate in closed position, means operable by pressure fluid'for actuating said holding means, a valve for controlling the supply of pressure fluid to said actuating means, primary means'for biasing said valve to a predetermined position, secondary means for overcoming said primary bias, and means operatively related to said gate for rendering said secondary means inactive when said gate is in closed position.

6. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for operating said gate, means for releasably holding said gate in closed position, means for controlling said gate-operating means, a source of power for supplying power through said gate-operating controlling means to said gate-operating means, means for actuating said holding means, means for cutting off said supply of power, means for controlling said cut-ofi means, means operated by pressure fluid for preventing operation of said cut-01f control means, and means operatively related to said holding means for controlling the supply of pressure fluid to said preventmg means.

7. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, a servo-motor for operating said gate, means for releasably holding said gate in closed position, a regulating valve for controlling said servo-motor, a source of fluid under pressure for supply ing pressure fluid through said regulating valve to said servo-motor, a valve for shutting off said supply from said source, means for controlling said shut-0H valve, means operated by pressure fluid for preventing operation of said shut-0H valve, and means operatively related to said holding means for controlling the supply of pressure fluid to said preventing means.

8. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, a servo-motor for operating said gate, means for releasably holding said gate in closed position, a regulating valve for controlling said servo-motor, means for releasably holding said regulating valve in the gate-closed position, means whereby s a i d regulating-valve-holdingmeans may move toward released position a predetermined amount without permitting movementof said regulating valve, and means responsive to said predetermined movement for causing release of said gate holding means.

9. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, a servo-motor for operating said gate, means for releasably holding said gate in closed position, a regulating valve for controlling said servo-motor, means for releasably holding said regulating valve in the gate-closed position, means whereby s a i d regulating-valve-holdingmeans may move toward released position a predetermined amount without permitting movement 01" said regulating valve, means responsive to said predetermined movement for causing release of said gate holding means. and means responsive to complete release of said gate holding means for causing movehaving a gate for controlling the admission of operating fluid thereto, a servo-motor for operating said gate, means for releasably holding said gate in closed position, a regulating valve for controlling said servo-motor, means for releasably holding said regulating valve in the gate-closed position, means whereby s ai d regulating-valve-holding means may move toward released position a predetermined amount without permitting movement of said regulating valve, means responsive to said predetermined movement for causing release of said gate holding means, means responsive to complete release of said gate holding means for causing movement of said regulating valve to gate-opening position, and means responsive to movement of said gate from closed toward open position for maintaining said last named means in action.

11. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, a servo-motor for operating said gate, means for releasably holding said ate in closed position, a regulating valve for controlling said servo-motor, means for releasably holding said regulating valve in the gate-closed position, means whereby said regulating-valveholdingmeans may move toward released position a predetermined amount without permitting movement of said regulating valve, means responsive to said predetermined movement for causing release of said gate holding means, means responsive to complete release of said gate holding means for causing movement of said regulating valve to gate-openin g position, and means for prodetermining the limit of said movement of said regulating valve in accordance with the position of said gate.

12. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, a servo-motor for operating said gate, a regulating valve for controlling said servo-motor, means for releasably holding said regulating valve in the gate-closed position, means Whereby said regulatingvalve-holding-means may move toward released position a predetermined amount without causing effective movement of said regulating valve, a source of fluid under pressure for supplying pressure fluid through said regulating valve to said servomotor, a valve for shutting ofl said supply,

and means operable by pressure fluid from of operating'fluidthereto, aservo motor for operatingv F said gate a regulating valve'ior controlling :said-servdmotor, means for re leasaloly holding said regulating valve in the gate closed positioma source-of fluid under pressure for supplyingpressure-fluid to said servo-motorthrough' said regulating valve, a valve for shutting off said supply, and means operablehy pressure fluid from the discharge side'of said shut-0H valve for controlling said regulating-valveholding means.

I L Ina control system for a prime mover having agate for controlling the admission of operating fluid thereto, a servo-motor for operatingsaid gate, a regulating: valve for controlling saidservo-motor, means for releasably holding said regulating valve in the gate-closed position, a source of fluid under pressure for supplying pressure fluid to said servo-motor through said regulating valve, a valve for shutting olT said supply, means for releasably'holding said gate in closed position, means operable'by pressure fluid from the'dischargesideof' said shut-off valve for controlling said regulating-valve-holdingmeans, and means responsive to release of said holding" means for controlling said last namedrmeansz Y 15; In a control system for a prime mover having: a gate for controlling the admission ofoperating fluid thereto, a servo-motor for operating said gate, a regulating valve for controlling said servo-motor, means for releasably holding said regulating valve in the gate=closed position, a source of fluid under pressure for supplying pressure fluid through saidIregulating valve to said servo-motor, a valve for shutting off said supply, means operalole by pressure fluid from the discharge side ofsaid shut-off valve for controlling said regulating-valve holding means, and common means for controlling said shut-off valve and said lastnamed means.

16. In a control system for a prime mover having a gate for controlling the admission otoperating fluid thereto,a-servo-motor for operating saidgate, a regulating valve for controlling said servo-motor, means for controlling said regulating valve in response to a predetermined condition of; said prime mover, additional means for controlling said regulating value,includinga floating lever having a floatin-gfpivot, means operatively related to oneend of said floating leverand positioned inaccordance with said gate, and means operatively-related to the other end of said floating lever and operatively related to said regulating valve. 7

17, In a controlsys tem for a prime" mover having a gateforcontrolling the admission Ofoperatin-g fluid thereto, a servo-motor for operating said gate, a regulating valve for controlling said servo-motor, means for controlling 'said regulating valve including a operatively related to one end of said floating lever and positioned in accordance with said. gate, means operatively related to the other end of said floating lever and operatively related to said regulating valve, and adjustable means having alost motion connection With'said floating pivot for adjusting the limitof motion of said pivot.

18. In a'control system for a prime mover having a gate for controlling the admission-of operating fluid thereto, a servo-motor for operating said gate, a regulating valve for controlling said servo-motor, means for releasably holding said: gate in closed position, means for controlling-said holding-means, means for cont-rolling.saidregulating valve includinga floating lever having a floating pivot, means operatively related to one end of said floating lever and positioned in accordance With said gate, means operatively related to the other end of said floating lever and operatively related to said regulating valve, and means operatively related to said floating :pivot for controlling said gate-holding controlling means.

19. In a control system fora prime mover having a gate controlling the admissionof operating fluid thereto, means for operating said gate, means'for controlling said gateoperating means, 'means for; limiting the maximum gate opening independently of the effect of said gate-operating-controlling means, means including anelectromotive device operatively=connected-to said limiting means for setting said limiting means, and means manually operable for setting said limiting means independently of actuation of said electromotive device.

20. In a control system for a prime mover havinga gate for controlling the admission of operating fluid thereto,-a servo-motor for said gate, a regulating valve for said servomotor, means for releasably holding said gate in the closed position, a supplyof fluid under pressure for supplying pressurefiuid tosaid servo-motor through said regulating valve, a valve for shutting ofl='saidsupply, means for limiting the maximum gate opening, means for automatically, causing opening of said shut-oflva lve, release of said gateholding means and movement of said regulating valve to gate-open position, and manually operable means interlocked With said limiting means for causing opening of said shut-off .valve and release of said gateholding :means only. V

21. Ina control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for, operatingsaid gate, means for controllingsaid gateoperating means,.means for releasably holding said gate-operating-controlling means in gate-closed position, and means for causing movementin the releasingdirection of said holding means inoluding two pistons operable by pressure fluid there being a lost motion connection between said pistons.

22. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for operating said gate, means for controlling said gate-operating means, means for releasably holding said gate-operating-controlling means in gate-closed position, means for causing movement in the releasing direction of said holding means including two pistons operable by pressure fluid there being a lost motion connection between said pistons, means for releasably holding said gate in closed position, and means operatively connected with said gate-holding means for controlling the admission of pressure fluid to one of said pistons.

23. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, a servo-motor for said gate, a regulating valve for said servomotor, a source of supply of fluid under pressure for supplying said servo-motor with pressure fluid through said regulating valve, a pressure fluid valve for shutting off said supply, means operable by pressure fluid for releasably holding said gate in closed position, means for releasably holding said regulating valve in the gate-closed position, means for causing movement in the releasing direction of said regulating valve holding means including two pistons operable by pressure fluid, a master valve controlling said shut-ofl valve and one of said pistons, means controlled by said gate-holding means for controlling the other of said pistons, and a valve controlled by said first named piston for controlling said gate-holding means.

24. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for operating said gate, means for controlling the supply of motive power to said gate operating means, means for releasably holding said gate in closed position, a motive device for operating said holding means, means for controlling said motive device including means operable by pressure fluid, means including amaster valve for controlling said controlling means for" said motive power supply and for controlling the supply of pressure fluid to said pressure fluid-operable means, and means operatively related to said holding means for limiting the motion of said master valve stem in a predetermined direction.

25. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for operating said gate, means for releasably holding said gate in closed position, means operable by pressure fluid for actuating said holding means, a valve for controlling the supply of pressure fluid to said actuating means, means including a lever operatively related to said valve biasing said valve to the open position, means including a second lever acting against said first named lever to overcome said bias, and means including a lever operatively related to said gate and having a lost motion connection with said second lever whereby said second lever is rendered inactive when said gate is in closed position.

26. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for operating said. gate, means for releasably holding said gate in closed position, means operable by pressure fluid for actuating said holding means, a valve for controlling the supply of pressure fluid to said actuating means, means includin a lever operatively related to said valve biasing said valve to the open position, means including a second lever acting against said first named lever to overcome said bias, means including a lever operatively related to said gate and having a lost motion connection with said second lever whereby said second lever is rendered inactive when said gate is in closed position, means for supplying power to said gate operating means, means for controlling said supply of power, and a lever having an operative connection with said first named lever and with said powersupply controlling means for causing opening of said gate and opening of said powersupply controlling means.

27. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for operating said gate, means for controlling said gateoperating means, means for releasably holding said gate-operating-controlling means in gate-closed position, means for causing movement in the releasing direction of said holding means including two pistons operable by pressure fluid there being a lost motion connection between said pistons, one of said pistons being provided with a rod operatively related to said holding means, means for bias ing said rod to holding position, and means for biasing the other piston to holding position.

28. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, means for operating said gate, means for controlling said gateoperating means, means for'releasably holding said gate-operating-controlling means in gate-closed position, means for causing movement in the releasing direction of said holding means including two pistons operable by pressure fluid there being a lost motion connection between said pistons, one of said pistons being provided with a rod operatively related to said holding means, means for bias ing said rod to holding position, means for biasing the other piston to holding position, means for releasably holding said gate in closed position, and means operatively connected with said gate-holding means for controlling the admission of pressure fluid to said other piston.

29. In a control'system for a prime mover having a gate controlling the admission of operating fluid thereto, means for operating said gate, means for controlling said gateoperating means, means for limiting the maximum gate opening independently of the efiect of said gate-operatingcontrolling means, means including a shaft operatively related to said means for limiting the maximum gate-opening for adjusting the same, an electromotive device, a worm and worm wheel drivable by'said electromotive device, means between said worm wheel and said shaft whereby said worm wheel may positively drive said shaft in either direction and said shaft may be rotated in either direction independently of said worm'wheel.

30. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, a servo-motor for operating said gate, a regulating valve for controlling said servo-motor, means for releasably holding said regulating valve in the gate-closed position, means for causing movement of said regulating valve to gate-opening position when said holding means releases said valve, and means for predetermining the speed at which said gate opens in cluding means for positioning said regulating valve in predetermined gate-opening positions in accordance with the position of said gate.

31. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, a servo-motor for operating said gate, a regulating valve for controlling said servo-motor, a stem for said regulating valve, a rod having a lost motion connection with said stem, means for biasing said connection to take up said lost motion, means for moving said rod against said bias, and means for predetermining the speed at which said gate opens including means for positioning said regulating valve stem in predetermined gate-opening positions in accordance with the position of said gate.

32. In a control system for a prime mover having a gate for controlling the admission of operating fluid thereto, a servo-motor for operating said gate, a regulating valve for controlling said servo-motor, a stem for said regulating valve, a rod having a lost motion connection with said stem, means for biasing said connection to take up said lost motion, a lever having a lost motion connection with said rod, means for biasing said last named connection to take up said lost motion, means for moving said rod against both of said biasing means, and means for predetermining the limit of movement of said regulating valve stem in accordance with the position of said gate.

In testimony whereof, the signatures of the inventors are aflixed hereto.

CHARLES B. TAYLOR. CARL SCHINDLER. 

